Process of making punches and dies.



s. D. HARTOG. y PROCESS 0F MAKING PUNCHES AND DIES.

APPLICATION FILED JULY 3, 1912.

1,070,889. Patentgd Aug. 19, 1913.

3 SHEETS-SHEET 1.

S. D. HARTOG. PROCESS 0F MAK-INGPUNGHES AND DIES. APPLIGATIN FILED JULY a, 1912.

1,070,889. Patented Aug.19,1913. .D

, 3 SHEETS-SHEET 2.

JJ J4 /5 J4 V547/?" 7' S. D. HARTOG. PROCESS OP MAKINGl PUNGHES AND DIES.

APPLIGATION FILED JULY 3, 1912.

1,070,889, l Patented Aug. 19, 1913.

3 SHEETS-SHEET 3.

mil. ull',

on the die block, and these plates term together a series ot spaced punch receiving apertures in which the punches are positionyedl and located in assembled relation. The plates for both the punch and die are duplicate and interchangeble, and are so shaped as to form parts of two adjacent apertures. These plates are produced wholly by punching operations, and the process oi forming these plates will now be described.

lleterring more particularly to lligs. l to 5 inclusive, l0 designates a die block et ordinary construction provided with die apertures ll and l2, which die apertures are gii'en considerable draft as shown. li punch block or holder 13 is provided with punches l-l and l5 cooperating with the die apertures ll and l2, and the punch l5 is provided with the usual centering pins lli. 'llhe punch and die will punch the aperture forming plates or elements 17 from the sheet 22V and also form the screw receiving holes therein.

rlhe aperture forming plates are made of comparatively thiclt steelt (one-eighth of an inch or over). This requires7 as is well known to those skilled in the art, that the punch be smaller than the coperating die aperture, the clearance increasing with the thickness olf the stock. ',lhe punching ll" as punched from the sheet `will therefore have the tace ld, which 'was engaged by the punch, smaller than the tace lll., which cngaged the die? so that the edge 2O will be inclined -instead ot square, while the lower corner olf the edge will be rounded as shown at 2l lig. l (on an exaggerated scalel. rlihe inside edge oit the punched sheet will also be inclined and rounded, but reversay trom the punching l?. '.lhis is a characteristic oit punched material, especially where the stock if* heavy.

'lhe punching l? termed as above will be entirely unsuitable in its present state. 'lhe tace 18 cannot be used either as a punch or as a die tace, as the edge 2O tapers in the wrong direction, While the rounded corners 2l ivill'render the face 19 unsuitable for cutting. ller the same reason the punched plate 22 is entirely unsuitable in its present state, as neither the tace which engaged the die, ner the tace Which engaged the punch can be used as a cutting tace. ln accordance With this invention the process is performed in two steps. ln the rst step the plate or punching is punched roughly to a size large enough to permit trimming. rlhis is indicated in llig. 2 where the dotted lines show the hnishcd size oit the punchinv. iin the second step the rough punching is trimmed to finished size by a finishing punch and die.

rlhe finishing or shaving punch and die consist of a die block 25 having a die aperture 2li and a nest 2T, and a punch 28 cooperating with the die aperture 26. rthis linishing punch and die are termed accunomen rately and the clearance between the punch and die is very smallyas rit is only necessary to take a small shaving from the edge ot the punched plate 17. lln practice the size of the punch and dieare practically the-same and only very slightly 'smaller than the size of the face 18. ln the punching operation the punching 'li'- is positioned in the nest with they tace '1S engaging the die. The product resulting from this Atuoeration will be the finished plate 29 having its edges practically square as shown in l*1 ig. d. lt will therefore `be seen that in accordance with this process a seriesof duplicate interchangeable plates 29 are formed wholly by punching operations. rllhese plates are accurately linished to size with their edges square to term a goed cutting edge, and are so shaped that each plateI 1will form a halt et two adjacent apertures as hereinafter de-v scribed. lt will be noted that the plates so formed are'th-ose parts `punched out tro1n the sheet.

'.lhe process ot assembling a die will now be described. lteierring to ltigs. (l and 7, Il() designates a die block or support. llhis die bloclr has termed therein apertures 3l which may be cast in the block. il. channel is cut in the upper faceot the die to provide positioning shoulders 3229 which shoulders are undercut as shown at 'l he Width ot' this channel as ,measured between the shoulders is made accurately to correspond to the length ot the plates 29. 'lhe plates are positioned in the channel formed in the die bloclt with the side edges olf these plates engaging one another and with the ends ot the plates engaging the shoulders 32. The plates are secured in position by means ott screws 3a passing through the'die bloeit and tapped into the plates. The holes in the die bloeit receiving the screws are ot larger diameter than the screws, and the apertures 3l are larger than the die apertures formed by the plates. rllhe die thus formed will have its die tace made up ot' a series of mutually engaging plates positioned one by the other in coiiperative relation to form a series of spaced die apertures.

Referring now to Figs. 8 and 9, 35 designates a punch bloclr or holder which is termed with an annular recess 36 and with a larger annular recess forming shoulders 37. It series ol the plates 29 are mounted in the annular recess and are secured in position by means oit screws 38 passing through the apertures in the plates 29. The screws are ot slightly smaller diameter thanthe apertures in the plates. The plates 29 will thus be positioned by their mutual engagement with one another and by the engagement et the ends ot the plates with the shoulders 37, and these plates term together a plurality ot apertures identical with the die apertures and spaced in identically the same relation.

These apertures receive the punches 39 as shown in the drawings. The channel 36 is slightly Widerthan the punches as shown in Fig. 8, and the punches are therefore located and positioned Wholly by the aperture forming plates. Preferably these plates are mounted in layers as shown so as to provide more extended bearings for the punches. After the punches are in position they are secured as positioned by means of screws 4() extending through enlarged countersunk holes in the punch block and tapped into the punches, and the countersunk holes are then filled up With babbitt 41. This method of securing the punches, by only filling the -countersunk fastener receivmg holes, is preferable over the old method in which the punches were .secured by a large mass of babbitt, as the shrinking of a large mass will often displace the punches.

It Will be noted'that t-he face 18 of the punching which` originally engaged the rately locating and positioning the punches,

are duplicate' and interchangeable. They therefore require for their manufactureA only the accurate production of the .master punches and dies, and one set of these master punches and dies can be used for manufacturing an indefinite numberof plates and therefore an indefinite number of punches and dies. The plates are small and comparatively thin; the required heating and cooling for hardening and tempering will therefore not cause distortion and cracking as is the case in the manufacture of block dies. This invention ltherefore results in a process which has a low cost of reduction, a low cost of apparatus instal ation and maintenance, and has the capacity of accurate duplication and indefinite reproduction.

In accordance with this process the edges of a series of aperture forming plates are so as to include the die-,apertures formed'by the plates on the die block and which receive the punches in the operation of punching, as well as the apertures formed. by the plates on the punch holder and which receive and permanently position the punches thereon.

While this invention is particularly adapted for manufacturing multiple or compound punches and dies for producing laminas of electrical machinery, it is by no means limited to this specific use, but its application may be general.

of the process, within the scope of the claims, without departing from the spirit of this invention, and it` is therefore to be understood that this 'invention is not to'be limited to the specific details described and shown.

Having thus described the invention what is claimed is:

The process of making multiple punches and dies which comprises forming the edges It is further obvious that. various changes may be made in the details v of a series of aperture forming plates in duplicate by punching Vso that each plate wi]l have a die-cut contour providing duplicate interchangeableedge locating means, and assembling the plates so formed in mutualcontour engagement on a holder or block to form in mutual assembly a plurality of accurately spaced punch receiving apertures.

In testimonywhereof I aiiix my signature in presence of two Witnesses.

STEPHEN D. HARTOG.

Witnesses:

'A. F. BEYER,

FRANKLIN MILLER. 

